The present invention relates to insulating building enclosures, particularly of the type having large glazing areas, such as greenhouses and other solar oriented buildings. As used herein, "glazing" refers not only to glass areas, but to other optically and/or infrared range transparent walled and/or roofed buildings and "buildings" as used herein includes vehicles as well as static structures and enclosures. The "glazing" may also include large area openings.
Within the greenhouse industry, there has been the longstanding recognition of the need to conserve energy and/or plant temperature at night by providing heat curtains which are stored on the north wall by day (a greenhouse usually runs east to west), such curtains being extended at night or on cloudy days to go across the lower part of the greenhouse and spread out to comprise a horizontal blanket. Such curtains and/or vertical curtains have also been used for artificial daylight control in connection with plant control purposes. The state of the art in terms of published disclosures is exemplified in U.S. Pat. Nos. 4,064,648, 4,027,437, 3,874,114, 3,481,073, 3,924,150, 3,249,682, and 2,193,921. But the principal products in the field (where any form of thermal curtain is used at all) are closest to those of the Gibbons and Yoshida disclosures (2,193,921 and 3,481,073, respectively).
It is an important object of this invention to provide an economical heat curtain of the class described, usuable in a variety of solar-oriented buildings as characterized above.
It is a further object of the invention to provide low capital and maintenance cost consistent with the preceding object.
It is a further object of the invention to provide ease of deployment and removal of the heat curtain, consistent with one or more of the preceding objects.
It is a further object of the invention to provide ease of adjustment of insulation value consistent with one or more of the preceding objects.